Hydraulic brake or dynamometer



Dec. 30, 1941. G. H. WALKER HYDRAULIC BRAKE 0R DYNAMOMETER Filed Oct.18, 1959 4 Sheets-Sheet l hventar Attqmeg Dec. 30, 1941; G. H. WALKERHYDRAULIC BRAKE OR DYNAMOMETER Filed Oct. 18, 1939 4 Sheets-Sheet 3 Dec.30, 1941. G. ,4. WALKER 2,267,852

HYDRAULIC BRAKE OR DYNAMOMETER Filed Oct. 18, 1939 4 Sheets-Sheet 4 (1""L'T '5 d d D (1+ 1 i i 1 Patented Dec. 30, 1941 HYDRAULIC BRAKE RDYNAMOIVIETER George Henry Walker, Worcester, England, as-

signor to Heenan & Froude Limited, Worcester,

England Application October 18, 1939, Serial No. 300,091 In FranceAugust 18, 1939 3 Claims.

This invention relates to improvements in hydraulic brakes anddynamometers of the type in which a'vaned element mounted on a rotaryshaft circulates water or other suitable liquid to and from a similarvaned element which is fixed in the casing of the apparatus.

It is well known that when dynamometers of this type are employed fortesting or other purposes involving the destruction of considerableamounts of power, the relative velocity between the water and theapparatus is sufiiciently high to endanger the life of the working partsby erosion or by erosion-corrosion and it is the object of the presentinvention to reduce damage to the working parts by avoiding, as far aspossible, the creation of harmful eddies in the vicinity of thevulnerable parts of the dynamometer.

To attain this object according to the invention the parts of thedynamometer with which the working liquid comes into contact with a highvelocity are so shaped that the liquid will flow over the surfacethereof smoothly and without generating appreciable turbulence.

The invention is illustrated in the accompanying drawings and will bedescribed with relation thereto. In these drawings:

Fig. 1 is a side view of a hydraulic dynamometer in which the powerabsorption is regulated by sluice gates.

Fig. 2 is a transverse section thereof.

Fig. 3 is a section on line 3-3 Fig. 2 showing the sluice gates whichcontrol the power of the apparatus in their open position.

Fig. 4 is a developed section of part of the rotating and non-rotatingelements.

Fig. 5 is a face view of the vaned element afiixed to the casing.

Fig. 6 is a view looking in the direction of the arrow 6 shown in Fig.4.

Fig. 7 is a vertical section of a modified form of the rotatingvanedelement.

Fig. 8 is a developed section of a part thereof.

Fig. 9 is a vertical section of one of the sluice ates.

Fig. 10 is an end view thereof.

Fig. 11 is a plan thereof.

Fig. 12 is a plan of the two sluice gates in their closed position andshowing in section the curtain plates between which they slide.

Fig. 13 is a detail face view of the curtain plates.

Fig. 14 is a detail view of the top plates in which the sluice gatesslide.

The hydraulic dynamometer is of the usual type with a casing A to whichis affixed the liners A in which the non-rotating vaned elements A areformed and a rotating shaft B to which is affixed the rotor B carryingthe rotary vaned elements B The casing A is mounted so as to be capableof a slight oscillating movement and is connected to the measuring andweighing apparatus C by the arm C The water or other liquid is suppliedthrough the inlets a connected to the annular space a and passes to thecoacting vaned elements A B through channels a in the vanes a of themember A The water or liquid leaves the elements A, B at thecircumferential edge I) from which is passes to the annular chamber bconnected to the outlet b. The power which the dynamometer is capable ofabsorbing is regulated by the sluice gates D which slide between the twovaned elements A and E the screws d by which they are operated beinggeared together so that the two gates will be moved in or out in unisonby a single operating handle.

In a dynamometer of the type to which the invention relates (which hasbeen briefly described in the preceding paragraph) two of the pointswhere erosion occurs are at the co-acting edges of the vanes a dividingthe non-rotating element A into a series of pockets and the edges of thevanes b similarly dividing the rotating elements B According to theinvention to minimise this erosion the edges of the vanes 19 01 therotating element B are rounded or streamlined at b as shown in Fig. 4.This avoids the impact of a fast-flowing jet of water striking a flatsurface of the vane b and enables the water to flow smoothly over themetal surfaces. Similarly the edges of the vanes a of the non-rotatingelement A (these vanes being shaped to return the water to the pocketsformed by the vane b of the rotating element B at a point near the shaftB) are rounded or streamlined at a as shown in Figs. 4 and 8. Some orall of the vanes a (usually alternate vanes) are formed with enlargedbosses a through which the water inlet channels a are bored, andhitherto, the shape of such bosses has been such as to present a suddenobstruction to the flow of water, with the consequence that eddies areformed in the vicinity of the bosses, tending to promote erosion.According to the present invention to overcome these objections thebosses a are streamlined smoothly into the material of the vane 11 asshown at a" in Fig. 6 whereby the water will flow smoothly over thebosses without producing turbulence and consequent erosion.

Moreover the section of the sluice gates D interposed between the vanedelements A and B by which the power consumed is regulated, has hithertobeen square with the face and the water impinging upon the flat faces ofthe gates becomes very turbulent leading to erosion of the gatesparticularly in the vicinity of the leading edges d thereof. To overcomethis according to the present invention as shown in Figs. 9 to 12 theleading edges d of the sluice gates D are rounded on the outer side sothat the jet of water when flowing from the rotor in the approximatedirection of the arrows 2 i divided by the leading edge d and flowssmoothly over the metal surfaces. Furthermore instead of a flat surfaceof metal being presented to the water leaving the rotating element B inan approximately tangential direction and at a high velocity openings (1are formed which permit the water to fiow past the sluice gates into thespace a behind them which, being filled with water, receives the impactand dissipates it without harm. The weight of the sluice gates iscarried upon rubbing faces 11 near the middle of their width with theopenings d between and at each side of them.

The two sides of each sluice gate D are connected together by a bandplate D in which, according to the present invention, holes 61 areformed near the sides so as to permit water escaping between therotating element B and the inner surface of the side plates of thesluice gates D to find its way into the water space 41 Despite the abovementioned precautions to avoid turbulence, there still remainsunavoidably a gap between the faces of the pair of sluice gates D,through which water leaving the rotor can impinge on the adjacent facesof the casing A. As the latter is generally made in cast iron, it isliable to damage by this impact, and to prevent this occurringprotecting plates E, of a material highly resistant to erosion andcorrosion, are mounted in recesses in the interior vertical walls of thecasing to form liner elements and secured therein by screws which, aftertightening, are pegged; or they may be fixed in any other suitablemanner as shown in Figs. 3, 12 and 13. Similarly the plates E of amaterial highly resistant to erosion or corrosion may be secured to thecasing to form the guide surfaces for the sluice gates as shown in Figs.2, 3, 9, 10, and 14. Similar plates may also be affixed to other partsof the casing to protect them against erosion.

Protecting sleeves of a material highly resistant to erosion andcorrosion may surround the rotor shaft B near the boss of the rotor Band adjacent to the glands through which the shaft B projects. Plates orwashers also of a material highly resistant to erosion or corrosion mayalso be used to surround the enlarged portion of the shaft on which therotor B is secured and the keyways in which the afiixing keys arelocated.

Instead of sleeves plates or washers of corrosion resisting materialbeing attached to these parts they may be sprayed or otherwise coatedwith a corrosion resisting material the object in either case being toprotect them from attack by water.

What I claim as my invention and desire to protect by Letters Patent is:

1. A hydraulic dynamometer of the type referred having a pair of sluicegates sliding between the vaned elements for controlling the powercapable of being absorbed by the dynamometer, said sluice gates beingformed with rounded leading edges and having apertures therein for thepassage of liquid to the space behind.

2. A hydraulic dynamometer of the type referred having a pair of sluicegates sliding between the vaned elements for controlling the powercapable of being absorbed by the dynamometer, each of said sluice gatesbeing formed with two side plates having rounded leading edges andhaving apertures therein for the passage of liquid to the space behindand a plate connecting the two side plates having apertures therein topermit any liquid escaping between the rotating element and the plate tofind its way into the space behind the latter.

3. A hydraulic dynamometer of the type referred having a pair of sluicegates sliding between the vaned elements for controlling the powercapable of being absorbed by the dynamometer, each of said sluice gatesbeing formed with two side plates having rounded leadingedges and havingapertures therein for the passage of liquid to the space behind and aplate connecting the two side plates having apertures therein to permitany liquid escaping between the rotating element and the plate to findits way into the space behind the latter and plates of material highlyresistant to corrosion and erosion secured to the casing adjacent to thegap between the pair of sluice gates.

GEORGE HENRY WALKER.

